Process for making a free flowing soap-nonionic detergent

ABSTRACT

Novel particulate blends of soap and liquid nonionic surfactants and a method for preparing same, is disclosed. The new method includes the combination of an appropriate fatty acid with the liquid nonionic surfactant before saponification of the acid. The novel particulate blends are dry, non-tacky and free flowing and are suitable for post addition to spray dried detergent powders or for use by themselves or with builders as final detergent formulations.

United States Patent 1 Mostow Sept. 23, 1975 1 PROCESS FOR MAKING A FREE FLOWING SOAP-NONIONIC DETERGENT [75] Inventor: John H. Mostow, Metuchen, NJ.

'[73] Assignee: Colgate-Palmolive Company, New

York, NY.

[22] Filed: Mar. 14,1974

21 Appl.No.: 451,023

Related U.S. Application Data [52] U.S. Cl. 252/370; 252/108; 252/132; 252/134; 252/368; 252/369; -252/DIG. 1 [51] Int. Cl. C11D10/04;C11D 11/04; C1 1D 13/10; CllD 17/06 [58] Field of Search 252/89, 108, 109, 117, 252/121, 132, 134, 368, 369, 370

[56] References Cited UNITED STATES PATENTS 1,571,625 2/1926 Dawes 252/368 1,971,375 8/1934 Hoyt 252/368 X 1,999,184 4/1935 Ellis 252/368 X 2,382,531 8/1945 Auer 252/370 2,543,744 3/1951 Fox 252/132 2,595,300 5/1952 Safrin 252/109 2,774,735 12/1956 Becher.... 252/117 2,875,153 2/1959 Dalton 252/132 2,947,701 8/1960 Ruff 252/109 3,247,121 4/1966 Hendricks 252/117 FOREIGN PATENTS OR APPLICATIONS 903,781 8/1962 United Kingdom 252/117 750,495 6/1956 United Kingdom 252/117 733,416 7/1955 United Kingdom....' 252/132 Primary Examiner-Dennis E. Talbert, Jr. Assistant Examiner-Dennis L. Albrecht Attorney, Agent, or Firm-Kenneth A. Koch, Esq.; Murray M. Grill, Esq.; Herbert S. Sylvester, Esq.

[5 7 ABSTRACT Novel particulate blends of soap and liquid nonionic surfactants and a method for preparing same, is disclosed. The new method includes the combination of an appropriate fatty acid with the liquid nonionic surfactant before saponification of the acid. The novel particulate blends are dry, non-tacky and free flowing and are suitable for post addition to spray dried detergent powders or for use by themselves or with builders as final detergent formulations.

3 Claims, No Drawings PROCESS FOR MAKING A FREE FLOWING SOAP-NONIONIC DETERGENT This is a divisionalof application Ser. No. 377,678 filed July 9, 1973, now US. Pat. No. 3,814,692, which is a continuation of Ser. No. l67,452, filed July 29, 1971, now abandoned.

The present invention relates to heavy duty, particulate, detergent formulations. Specifically the invention provides a method for incorporating relatively large amounts, typically above about 5 percent by weight, of liquid nonionic surfactants into heavy duty particulate detergent formulations. More specifically, a method for combining liquid nonionic surfactants with soap, in free flowing particulate form, is provided by the invention. The new soap-nonionic particulate material has ap proximately the same ionsity as spray dried detergent powders and can be utilized, in combination with builders, as a final detergent formulation, or it can be very advantageously post added to spray dried detergent formulations.

The most commonly used surface active agents in heavy duty detergent formulations are anionic compounds having detersive properties. Typical of these anionic compounds are the higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates. These synthetic detergents are very effective in removing dirt from textile fabrics when utilized in conjunction with phosphate builders which function to soften the water being used andto provide detersive action. However, considerable controversy exits today as to the efficacy of utilizing phosphate compounds in detergent formulations due to their alleged causation of the eutrophication' process in lakes, rivers, and streams. Although the eutrophication process, wherein an excessive growth of aquatic plant life is promulgated in natural water bodies, is not completely understood, it is alleged that the phosphate compounds present in detergent containing waste water are a prime factor in promoting this phenomenon. it has been discovered that when the phosphate content of a detergent formulation is substantially reduced,

the nonionic surfactants appear to provide detergent properties that are superior to anionics in the same reduced phosphate content formulation. Apparently the detersive effectiveness of nonionic surfactants is effected much less by water hardness than that of the commonly used anionic surfactants. ln the event that the phosphate builders are totally or partially removed from detergents, the incorporation of progressively .larger amounts of nonionic surfactants into detergent formulations either in place of or in addition to anionic surfactants may become very desirable.

3 At present, small amounts of nonionic surfactants are added to detergent formulations, primarily to reduce the amount of foam generated during the washing cycle. However, it has been found that when a substantial amount, typically above 5% by weight, of nonionic surfactants is incorporated into the detergent slurry before ,spray drying, a pluming problem, manifested by a dense black smoke being discharged from the spray :tower, may be encountered.

i The combination of soap with a liquid nonionic surfactant in a detergent formulation is particularly advantageous since it results in a reduction or elimination of the high sudsing that is characteristics of anionic surfactants in detergent formulations. Prior art attempts to combine soap with liquid nonionic surfactants has typically resulted in a gel like mass that ultimately separates into two phases, and is unsuited for use in combination with powdered detergents. The primary advantage of the present invention is a method for combining liquid nonionic surfactants with soap in a dry, free flowing particulate form that may be readily utilized in combination with builders as a final detergent formulation or post added to spray dried detergent formulations to significantly increase the nonionic surfactant content of the final detergent product.

The nonionic surfactant component of the invention is well known and may be defined as the reaction product' of ethylene oxide with a hydrophobic compound containing a carboxyl, mercapto, amido, amino or hydroxyl group. A preferred type of nonionic surfactant for use in accordance with the invention are ethoxylated long carbon chain alcohols. Typically, nonionic ethoxamers of this type have an eight to 20 carbon atom alkyl chain preferably 14 to 18 and an average of about four to 19, preferably 10 to 15, ethylene oxide units per molecule. The range of ethylene oxide content that provides the greatest detergency in these surfactants usually results in a material that is a viscous liquid at room temperature, and therefore unsuitable for direct addition to spray dried detergent powder. 7

The fatty acid component of the new particulate blends includes naturally occurring saturated fatty acids as well as commercially produced fatty acids derived by hydrogenating natural products such as coconut oil, palm kernel oil, babasu oil etc. The fatty acids of the invention are characterized by having a C to C carbon chain. Preferably the C to C saturated fatty acids derivedfrom beef and pork fat glycerides, and from palm, coconut and related oils are used. These acids are commonly known in the art as lauric (C nonionic by weight. in accordance with the invention,

the new method includes the intimate mixing of the fatty acid from which the soap is derived with the nonionic surfactant prior to saponification of the acid with a neutralizing agent to produce the soap. ln formulating the new free flowing blends, the fatty acid material is initially mixed with liquid nonionic material at an elevated temperature, usually between about 15.0F and 200F, until the two components become mutually soluble and form a relatively clear liquid. The clear solution is then neutralized by mixing with an alkali metal preferably sodium and potassium carbonate. The neutralized reaction mass is then permitted to cool to room temperature during which it puffs into a porous solid that can be mechanically broken up into a free flowing, non-tacky powder having a density approximately equivalent to that of spray dried detergent powders, typically between about 0.25 and 0.75 grams per cc, usually 0.34 grams per cc.

in accordance with a further specific aspect of the invention, the new method permits the production of a free flowing soap-liquid nonionic surfactant particulate blend having a nonionic content of up to about 50 percent by weight. The relatively high ethoxamer content of the new particulate blend permits a substantial increase in the nonionic surfactant content of powdered detergents while avoiding the handling, pluming and tackiness characteristics of prior art methods. For example, the post addition of the soap-nonionic surfactant material of the invention to a conventional pow dered detergent to form a 5050 percent by weight mixture results in a final product having a nonionic surfactant content of up to about 25 percent by weight.

The following specific examples are further illustrative of the nature of the present invention but it is understood that the invention is not limited thereto. All amounts and proportions are by weight unless otherwise indicated.

EXAMPLE 1 50 parts of a liquid ethoxylated fatty alcohol, having a 14 to carbon atom alkyl chain and an average of l l ethylene oxide units per molecule are mixed with 50 parts of lauric acid and heated to l80F to form-a clear solution. 100 parts of anhydrous sodium carbonate are mixed into the fatty acid-nonionic solution and the mixture is reheated to l80F and stirred until the neutralization reaction is complete. The mixing is then stopped and the reaction product is allowed to cool. During cooling the reaction product pufis to a porous solid that can be milled to particulate form. The resulting particulate material is dry, non-tacky and has a density of about 0.35 g/cc.

EXAMPLE 2 Example 1 is repeated with similar results using liquid nonionic surfactants derived by ethoxylating fatty alcohols having the following alkyl carbon atom chains and the indicated average number of ethylene oxide units per molecule.

Carbon atom Chain Average number of ethylene oxide units l6-l8 t2 l0-l4 7 lO-l4 4 l6-l8 ll l6-l8 6 l6-l8 l0 l6l8 19 All of the foregoing soap-nonionic particulate blends are dry, free flowing and very suitable for post-addition to typical spray dried detergent powders.

EXAMPLE 3 EXAMPLE 4 Example 3 is repeated, with similar results, using each of the nonionic surfactants listed in Example 2.

EXAMPLE 5 Example 3 is repeated, with similar results, using stearic acid in place of myristic acid.

EXAMPLE 6 Example 5 is repeated, with similar results using each of the nonionic surfactants listed in Example 2.

EXAMPLE 7 Example 3 is repeated, with similar results using palmitic acid in place of myristic acid.

EXAMPLE 8 Example 7 is repeated, with similar results, using each of the nonionic surfactants listed in Example 2.

EXAMPLE 9 C caprylic acid C capric acid C palmitic acid C myristic acid C palmitic acid C stearic acid 2.5 3 percent 2.0 3 percent 4.5 10 percent 8.0 10 percent l2.0 [5 percent 71.0 59 percent The ethoxamer-fatty acid mixture is heated to about l80F to form a clear solution and 50 parts of potassium carbonate and 50 parts of anhydrous sodium carbonate are mixed into the solution. The mixture is then EXAMPLE 10 Example 9 is repeated with similar results using a liquid nonionic ethoxamer having an alkyl chain of 16-18 carbon atoms and an average of 12 ethylene oxide units per molecule. A fatty acid mixture having the following composition is used.

C lauric acid C myristic acid C palmitic acid C stearic acid C stearic acid C arachidic acid C behenic acid l0l5 percent 20-40 percent 15-20 percent 25 percent 13.0 percent 8.0 percent 5.0 percent EXAMPLE I 1 Example 9 is repeated with similar results using a mixture of fatty acids having the following composition:

C, caprylic acid 5.0 percent C capric acid 60 percent C lauric acid 34.0 percent C myristic acid [5.0 percent C palmitic acid l4.0 percent Since the new soap-nonionic particulate blends are dry, non-tacky and free flowing and have about the same density as spray dried detergent powders, they are I ther with or without builders, as desired. Although the foregoing specific examples are presently preferred in the practice of the invention, variations may be made and equivalents may be substituted without departing from the spirit of the invention. Consequently, reference should be made to the following claims in determining the full scope of the invention.

l claim:

1. The method of forming free flowing detergent particles comprising the steps of:

a. intimately mixing a saturated fatty acid having from 12 to 18 carbon atoms with a liquid nonionic surfactant chosen from the group consisting of ethoxylated fatty alcohols having an alkyl chain of from eight to carbon atoms and from about four to about 19 ethylene oxide units per molecule, to produce a liquefied mass,

b. a moisture scavenger being present in said liquefied mass when potassium is said alkali metal to prevent said potassium carbonate from becoming deliquescent,

c. neutralizing said liquefied mass by adding an alkali metal carbonate in sufficient quantity to saponify said fatty acid,

d. said neutralizing step being performed at a predetermined elevated temperature suitable for saponifying said fatty acid,

e. mixing said liquefied mass during neutralization to insure uniform saponification of said fatty acid,

f. cooling the neutralized mass to room temperature,

g. said neutralized mass puffing to a porous solid during said cooling step and,

h. said neutralized mass including from about 10 to about 50 percent by weight of the nonionic surfactant and at least 50 percent by weight of the alkali metal soap of said fatty acid,

i. mechanically reducing said porous solid to particles having a density of from 0.25 to 0.75 grams per cc.

2. The method of claim 1 wherein,

a. said alkali metal is chosen from the group consisting of sodium and potassium and,

b. said fatty acid is chosen from the group consisting of lauric, myristic, palmitic and stearic.

3. The method of claim 1 wherein,

a. said predetermined temperature is between about F and 200F. 

1. MECHANICALLY REDUCING SAID POROUS SOLID TO PARTICLES HAVING DENSITY OF FROM 0.25 TO 0.75 GRAMS PER CC.
 1. THE METHOD OF FORMING FREE FLOWING DETERGENT PARTICLES COMPRISING THE STEPS OF: A. INTIMATELY MIXING A SATURATED FATTY ACID HAVING FROM 12 TO 18 CARBON ATOMS WITH A LIQUID NONIONIC SURFACTANT CHOSEN FROM THE GROUP CONSISTING OF ETHOXYLATED FATTY ALCOHOLS HAVING AN ALKYL CHAIN FROM EIGHT TO 20 CARBON ATOMS AND FROM ABOUT FOUR TO ABOUT 19 ETHYLENE OXIDE UNITS PER MOLECULE, TO PRODUCE A LIQUEFIELD MASS, B. A MOISTURE SCAVENGER BEING PRESENT IN SAID LIQUEFIELD MASS WHEN POTASSIUM IS SAID ALKALI METAL TO PREVENT SAID POTASSIUM CARBONATE FROM BECOMING DELIQUESCENT, C. NUETRAALIZING SAID LIQUEFIELD MASS BY ADDING AN ALKALI METAL CARBONATE N SUFFICIENT QUANTITY TO SAPONIFY SAID FATTY ACID, D. SAID NEUTRALIZING STEP BEING PERFORMED AT A PREDETERMINED ELEVATED TEMPERATURE SUITABLE FOR SAPONIFYING SAID FATTY ACID, E. MIXING SAID LIQUEFIED MASS DURING NUETRALIZATION TO INSURE UNIFORM SAPONIFICATION OF SAID FATTY ACID, F. COOLING THE NEUTRALIZED MASS TO ROOM TEMPERATURE, G. SAID NEUTRALIZED MASS PUFFING TO A POROUS SOLID DURING SAID COOLING STEP AND, H. SAID NEUTRALIZED MASS INCLUDING FROM ABOUT 10 TO ABOUT 50 PERCENT BY WEIGHT OF THE NONION SURFACTANT AND AT LEAST 50 PERCENT BY WEIGHT OF THE ALKALI METAL SOAP OF SAID FATTY ACID,
 2. The method of claim 1 wherein, a. said alkali metal is chosen from the group consisting of sodium and potassium and, b. said fatty acid is chosen from the group consisting of lauric, myristic, palmitic and stearic.
 3. The method of claim 1 wherein, a. said predetermined temperature is between about 150*F and 200*F. 